Triple-Band Reconfigurable Monopole Antenna for Long-Range IoT Applications.

Area of Science:

• * Electrical Engineering
• * Wireless Communication Systems
• * Antenna Design

Background:

• * The Internet of Things (IoT) relies on efficient wireless communication, with LoRa (Long Range) technology enabling long-distance, low-power connectivity.
• * Existing antenna solutions often lack reconfigurability to support multiple global LoRa frequency bands (433 MHz, 868 MHz, 915 MHz).
• * A need exists for compact, versatile antennas that can adapt to different regional LoRa deployments.

Purpose of the Study:

• * To design, fabricate, and validate a novel reconfigurable triple-band monopole antenna for LoRa IoT applications.
• * To achieve seamless operation across European, American, and Asian LoRa frequency bands (433 MHz, 868 MHz, 915 MHz).
• * To ensure the antenna offers high gain, efficient radiation, and an omnidirectional radiation pattern.

Main Methods:

• * Antenna design and optimization using CST Microwave Studio (MWS) software.
• * Implementation of a PIN diode switching mechanism for frequency reconfigurability.
• * Fabrication on an FR-4 substrate and subsequent measurement and comparison with simulation results.

Main Results:

• * A compact antenna (80 mm × 50 mm × 0.6 mm) was successfully fabricated and tested.
• * Achieved gains of 2 dBi, 1.9 dBi, and 1.9 dBi at 433 MHz, 868 MHz, and 915 MHz, respectively.
• * Demonstrated radiation efficiency exceeding 90% across all three bands with an omnidirectional H-plane pattern.

Conclusions:

• * The fabricated antenna accurately matches simulation predictions, validating the design.
• * The reconfigurable triple-band antenna is highly suitable for diverse LoRa IoT applications.
• * The antenna provides a compact, flexible, and energy-efficient solution for global LoRa communication.